<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
    <style>
        div{
            border: solid 1px #c7254e;
            border-radius: 10px;
            /*width: 200px;*/
            /*height: 100px;*/
        }
        .first{
            float: left;
        }
        .second{
            border: double 2px #000000;
            border-radius: 0px;
        }
    </style>
</head>

<body>
    <div class="first">
        <span>This is left float</span>
    </div>
    <div class="second">
        Sencond Div
    </div>
</body>
</html>